Republican state Senate Majority Leader Dean Skelos expects a series of ugly confrontations over rent regulations, school aid and other hot-button issues with newly elected Assembly Speaker Carl Heastie (D-Bronx) — and he’s looking to Gov. Andrew Cuomo for support, insiders say.

But Cuomo, allied in past years with the Nassau County-based Skelos on such key issues as gun control, same-sex marriage and legislative redistricting, has been under heavy attack from his political left because of his closeness to Republicans and is gearing up to help crush the GOP, not help Skelos, the insiders agree.

“The game has changed for Cuomo. He’s under increasing pressure from his political left and from Mayor [Bill] de Blasio for being Republican-friendly, and I don’t think Dean fully realizes that,’’ said a source close to Cuomo’s office.

Heastie is widely seen as even more to the political left than recently ousted and disgraced Speaker Sheldon Silver of Manhattan, and he’s making an ambitiously “progressive’’ agenda — including toughened rent regulations, which have long been opposed by the Senate GOP — his top priority, Assembly aides say.

“Dean is counting on Cuomo to protect him from Heastie,’’ said a source familiar with Skelos’ thinking.

“Dean will protect Cuomo from the excesses of his party’s left by blocking the worst of their legislation, and the governor will protect Dean and the Republicans by refusing to endorse their most radical measures. At least that’s the hope,’’ the source said.

But Democrats expect a highly popular Hillary Clinton to be their party’s standard-bearer for president next year, and believe she’ll bring huge numbers of Democratic voters to the polls, making it nearly impossible for Republicans to keep control of the Senate.

“Cuomo knows that with Hillary on the ticket, Senate Republicans may get crushed next year, and he’s starting to adjust his tactics accordingly,’’ the Cuomo source said.

Skelos, widely regarded as an uninspiring leader, is also feeling the heat from US Attorney Preet Bharara’s ongoing investigation of Albany corruption amid reports that the hard-driving prosecutor is closely examining the senator’s ties to Ruskin, Moscou Faltischek, the Long Island law firm that has been paying him as much as $250,000 a year.

Rumors persist that Skelos won’t be Republican leader for much longer and is eyeing retirement at the end of next year.

Sen. Catharine Young of Olean, who heads the Senate Republican Campaign Committee, is being whispered about as his likely successor.